<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        span{
            display: inline-block;
            width:100px;
          

            /* 针对于最后一行 */
            text-align-last: justify;
        }
    </style>
</head>
<body>
    <div class="demo">
        <div><span>昵称</span>:<input type="text"></div>
        <div><span>电子邮箱</span>:<input type="email"></div>
    </div>
</body>
</html>